Automatic workpiece loading arrangement for a grinder feed wheel

ABSTRACT

A loader arrangement is disclosed for advancing workpieces into recesses formed in fixturing stations carried by the grinder feedwheel; and comprises a reciprocating stripper blade which forces a workpiece into the fixture recess by means of an intermediary workpiece train in turn supplied from a vertical stack of workpieces formed from a bowl feeder which are stripped off by reciprocation of the stripper blade. The workpiece immediately preceeding the one loaded in the workpiece train is located and positioned in the loader chute to maintain the position of the workpiece in the recess as the feedwheel passes through the vicinity of the loader arrangement to allow immediate retraction of the stripper blade and full seating and wiping contact with the workpiece as the fixture station passes beyond the loader chute.

Uite States Patent [191 Fallon 1451 Oct. 16, 1973 AUTOMATIC WORKPIECELOADING ARRANGEMENT FOR A GRINDER FEED WHEEL 7 Inventor: Herbert J.Fallon, Beloit, Wis.

Assignee: The Bendix Corporation,

Southfield, Mich. I

Filed: Mar. 20, 1972 Appl. No.: 236,017

References Cited UNITED STATES PATENTS Primary ExaminerGerald M.Forlenza Assistant Examiner-Ge0rge F. Abraham Attorney-John R. Benefielet al.

57 ABSTRACT A loader arrangement is disclosed for advancing workpiecesinto recesses formed in fixturing stations carried by the grinderfeedwheel; and comprises a reciprocating stripper blade which forces aworkpiece into the fixture recess by means of an intermediary workpiecetrain in turn supplied from a vertical stack of workpieces formed from abowl feeder which are stripped off by reciprocation of the stripperblade, The workpiece immediately preceeding the one loaded in theworkpiece train is located and positioned in the loader chute tomaintain the position of the workpiece in the recess as the feedwheelpasses through the vicinity of the loader arrangement to allow immediateretraction of the stripper blade and full seating and wiping contactwith the workpiece as the fixture station passes beyond the loaderchute.

11 Claims, 5 Drawing Figures PATENIED 061 \6 I975 SHEET 10F 3 FIG. I

PATENTED BUT I 6 1975 SHEET 3 UP 3 QOI BACKGROUND OF THE INVENTION 1.Field of the Invention This invention concerns loader arrangements andmore particularly automatic loaders suited for high speed loading ofworkpieces into grinder feed mechanisms.

2. Description of the Prior Art Automatic loader mechanisms suitable forthe application described above have for the most part been limited togravity feed arrangements in which a supply of workpieces are allowed todescend by gravity from a supply hopper and exit at the loading point insynchronism with the passing of work holding recesses on the feedmechanism. This approach is suitable for many applications but for acertain number of configurations of the feed mechanisms and workpieces,a gravity feed is precluded because the necessary accurate seating ofthe workpiece by gravity is not possible or else necessary loading forcecannot be supplied by gravity because of the path the workpiece mustfollow to be seated. Additionally, certain limitations in the rate ofloading or the reliability of the loading process itself produced by agravity feed may be encountered in some situations.

Any attempt to provide positive loading of workpieces at a high rate ofspeed can on the other hand lead to bouncing or mispositioning of theworkpiece in the recess during the loading operation, which can jam themachine or cause other difficulties. Attempts to hold the workpiece inthe seated position by the positive loader could lead to limitations onthe rate of load and/or scoring of the workpiece as will be described.

Therefore, it is an object of the present invention to provide anautomatic workpiece loader arrangement which positively loads theworkpieces at a high rate of speed with a minimum incidence of workpiecemispositioning or scoring during the loading operation.

SUMMARY OF THE INVENTION This and other objects of the present inventionare accomplished in cooperation with the fixturing stations carried bythe grinder feedwheel and comprises a reciprocating stripper blade whichforces a workpiece into the fixture recess by means of an intermediaryworkpiece train in turn supplied from a vertical stack of workpieces fedby from a bowl feeder, which are stripped off by reciprocation of thestripper blade. The workpiece immediately preceeding the one loaded inthe workpiece train is located and positioned in the loader chute tomaintain the position of the workpiece in the recess as the feedwheelpasses through the vicinity of the loader arrangement to allow immediateretraction of the stripper blade and full seating and wiping contactwith the workpiece as the fixture station passes beyond the loaderchute.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary sectional view of atypical rotary work feedwheel and an associated fixture station showingthe relationship to a pair of automatic loader arrangements according tothe present invention.

FIG. 2 is a fragmentary and enlarged side elevational view of the rotarywork feedwheel shown in FIG. 1

showing a pair of fixture stations and the associated clampingmechanism.

FIG. 3 is an elevational enlarged view of one of the automatic loadersshown in FIG. 1 together with the fixturing associated with one of thefixture stations.

FIG. 4 is a plane view of a portion'of the loader and fixturing shown inFIG. 3. I

FIG. 5 is an enlarged view of the Section 5-5 taken in FIG. 4.

DETAILED DESCRIPTION In the following detailed description certainspecific terminology will be utilized for the sake of clarity and aspecific embodiment will be described in order to provide a completeunderstanding of the invention, but it is to be understood that theinvention is not so limited and may be practiced in a variety of formsand embodiments.

Referring to the figures and particularly FIGS. 1 and 2, a rotaryfeedwheel 10 of a type well-known in the art is depicted.

The rotary feedwheel 10 is mounted for rotation and carries a series offixturing stations 12 disposed about its periphery which are adapted toreceive objects which in this context are workpieces 14, FIG. 5, fromloader arrangements 16 disposed on either side of the feedwheel 10 to besubsequently carried between opposed grinding discs (not shown) byrotation of the feedwheel 10.

Each fixture station 12 includes a clamping mechanism 18, including apivotally mounted lever arm 20 and clamping member 22 pivotally mountedthereto which engages the workpieces 14 in the clamped position. Theclamping is accomplished by means of a chain (shown in phantom FIG. 2)engaging the lever arm 20 and arranged so that after each fixturestation 14 passes the loading arrangement 16 the geometry of chainsupport (not shown) causes the chain to depress the lever arm 20 so thatthe workpieces are clamped before entering the grind zone.

Inasmuch as this specific type of feedwheel clamping arrangement isknown in the art, and is not an essential part of the present invention,the description thereof is limited to the above, which is adequate tounderstand the present invention.

One of the loader arrangements 16 which is identical except for beingrightand left-handed is depicted in detail in FIGS. 3 and 4, togetherwith the recess fixture 24 associated with each fixture station 12.

Each fixture 24 provides a recess formed by a backplate 28 and twospacer sideplates 30 and 32 all fastened to a fixture block 34. Thedistance between spacer sideplates 30 and 32 is such that the workpiece14 will just slide therebetween while the backplate 28 serves toproperly orient the workpiece 14 when it is firmly seated thereon. Inconnection with this, it has been found that the workpiece 14 will seattruer on a pair of protuberances 36 and 38 on the backplate 28 ratherthan with an area contact which would result from direct seating on thesurface thereof.

The loader arrangement 16 includes a vertical chute structure 40 whichis adapted to receive workpieces 14 from a feeder source such as a bowltype hopper (not shown) and create a vertical stack of workpieces 14within the opening 42 as shown in FIG. 3.

Plates 44 and 46 which partially define opening 42 terminate above thesurface of the baseplate 48 so as to allow the bottom of the stackedworkpieces 14 to be moved forwardly from the stack, down the surface ofthe baseplate by means of a stripper blade 50 as best seen in FIG. 5.

The stripper blade 50 is reciprocated by means of an air cylinder 52which is controlled by suitable control circuitry and limit switches(now shown) so that as each fixture station 14 comes into registry withthe loading arrangement, the stripper blade 50 is reciprocated toadvance the bottommost workpiece down the baseplate 48.

The first reciprocation of the stripper blade 50 (assuming no workpieceshave been loaded) causes the bottommost workpiece 14 to advance intoengagement with a pair of spring retainers S4 and 56 secured to plate 44so that the workpiece is securely held against vertical movement oragainst inadvertent travel up or down the baseplate 48,-after which theair cylinder 52 immediately retracts the stripper blade 50 to preparefor the next cycle.

Another cycle of the stripper blade 50 advances the next workpiece fromthe stack down the baseplate 48 into engagement with the previouslyadvanced workpiece which has been held in position by the springretainers 54 and 56 which is in turn advanced by engagement with theanotherworkpiece into the recess 26 on the fixture station 14 which ispositioned in registry by suitable control circuitry and switches (notshown).

The stripper blade 50 is immediately retracted and the feedwheel 10 isadvanced out of registry with loading arrangement 16. During thisadvance, the workpiece 14 in the recess 26 and the workpiece 14 beingheld by spring retainers 54 and 56 are in contact along their leadingand trailing edges respectively, so that one wipes the other to insurethat the workpiece 14 in the recess is maintained in proper positiontherein seated against the protuberances 36 and 38 during the periodthat the fixture station 12 is in approximate registry with. the loadingarrangement 16. In connection with this process, the workpiece 14 inposition under spring retainers 54 and 56 is also guided and held inposition during advancement thereof by surfaces 58 and 60 of plates62'and 64 respectively forming guide rails along the baseplate 48. Thisarrangement prevents any tendency'towards cocking produced by the wipingaction described.

After the feedwheel 10 rotates sufficiently so that the particularfixture station 12 passed the loading arrangement. l6, guide rollers orfingers (not shown) of conventional design may be used to maintain theworkpiece in position until the clamping-mechanisms are actuated.

The advantages pieces 14' can-be betterappreciated by reference to FIG.wherein it can be seen that the stripper blade 50 must be substantiallythinner than the workpiece in order to insure that the stripper blade 50engages only a single workpiece 14 in spite of variations in thethickness thereof or slight mispositioning on the baseplate 48. Thisdifference in thickness creates a tendency for the stripper blade 50 tocause a tipping of the workpiece 14 during advance movement thereofsince the respective centerlines are caused to be offset to create aturning moment. This tendency is resisted while the workpiece 14 isbeing stripped from the stack and advanced into engagement with springretainers 54 and 56 by the limited overhead clearance with plate 44 andof this approach to loading the worksubsequently the spring retainers 54and 56 provide a downward resilient bias force. During the movement ofthe lead workpiece 14 in the train into the recess 16 however, controlof any tendency to tip is accomplished firstly by theworkpiece-to-workpiece edge contact which eliminates the tippingtendency created by offset contact which is the case with engagementdirectly by the stripper blade. Secondly, any slight tendency whichremains is reduced both by the limited clearance d (FIG. 2) between theclamping member 22 and the recess 26 bottom and by the engagement withthe workpieces 14 which is retained by the spring retainers 54 and 56.This engagement resists any upward movement, and if it does occur, thedownward resilient bias exerted by spring retainers 54 and 56 snaps theworkpiece downwardly back into position.

This engagement also prevents bouncing of the workpiece either as aresult of seating on backplate 28 or from this tipping movement, sincethe intermediate workpiece 14 is firmly held against lateral movement onbaseplate 48 by the spring retainers 54 and 56.

It is noted that this engagement can be maintained without delayingretraction of the stripper blade 50 which can be immediately retractedin preparation for the next cycle.

The wiping process noted above is also more trouble-free with aworkpiece-to-workpiece engagement since contact directly with thethinner stripper blade 50, has an increased tendency to score the edgeof the workpiece 14 in the recess.

From this description it can be appreciated that a simple loaderarrangement has been provided which is capable of high speed positiveloading of workpieces with a minimum danger of mispositioning ofworkpieces occurring as a result of the loading process.

It should also be apparent that many variations of the specificembodiment are possible within the scope of the following claims.

What is claimed is:

1. A system for feeding objects into a series of fixtures havingrecesses formed therein and moving past a loading point comprising: 1

loader chute means adapted to guide said object to said loading point;

means feeding objects into said loader chute means;

means for cyclically advancing objects in said loader chute means so asto cause the object at said loading point to be advanced into a recessin a fixture of said fixture series aligned with said loading point bymeans of engagement with another object in said loaderchute;

means locating and positioning the another object in said loader chuteat said loading point in engagement with said object advanced therebyintosaid recessas said fixture moves past said loading point, wherebysaid object is advanced into said recess and maintained therein by saidanother object at said loading point.

2. The system of claim 1 wherein said locating and positioning meansincludes spring retainer means engaging said object at said loadingpoint.

3. The system of claim 2 wherein said spring retainer means frictionallyengages said object as it movesto said" loading point.

4'. The system of claim 3 wherein said loader chute means includes guiderail means retaining said object at said loading point against movementcaused by engagement with said object advanced into said recess and saidmovement of said fixture past said loading point.

5. The system of claim 1 wherein said recesses include surfacespositively seating said objects as said objects are advanced into saidrecess aligned with said loading point and seated therein by engagementwith said object at said loading point.

6. The system of claim 1 wherein said means feeding objects into saidloader chute means includes means forming a stacking of said objects,said stack terminating at said loader chute means and also includesstripper means stripping the lowermost object from said stack andadvancing said lowermost object down said loader chute means.

7. The system of claim 6 wherein said stripper means includes a stripperblade narrower than the thickness of said objects as stacked, and meansfor reciprocating said stripper blade to cyclically strip off thelower-most object.

8. The system of claim 1 wherein said locating and positioning meansresists movements of said object at said loading points normal to saidloader chute means.

9. The system of claim 8 wherein said locating and positioning meansincludes spring retainer means engaging said object at said loadingpoint.

10. The system of claim 9 wherein said spring retainer meansfrictionally engages said object as it moves to said loading point.

11. The system of claim 10 wherein said loader chute means includesguide rail means restraining said object at said loading point againstmovement caused by engagement with said object advanced into said recessand said movement of said fixture past said loading point.

1. A system for feeding objects into a series of fixtures having recesses formed therein and moving past a loading point comprising: loader chute means adapted to guide said object to said loading point; means feeding objects into said loader chute means; means for cyclically advancing objects in said loader chute means so as to cause the object at said loading point to be advanced into a recess in a fixture of said fixture series aligned with said loading point by means of engagement with another object in said loader chute; means locating and positioning the another object in said loader chute at said loading point in engagement with said object advanced thereby into said recess as said fixture moves past said loading point, whereby said object is advanced into said recess and maintained therein by said another object at said loading point.
 2. The system of claim 1 wherein said locating and positioning means includes spring retainer means engaging said object at said loading point.
 3. The system of claim 2 wherein said spring retainer means frictionally engages said object as it moves to said loading point.
 4. The system of claim 3 wherein said loader chute means includes guide rail means retaining said object at said loading point against movement caused by engagement with said object advanced into said recess and said movement of said fixture past said loading point.
 5. The system of claim 1 wherein said recesses include surfaces positively seating said objects as said objects are advanced into said recess aligned with said loading point and seated therein by engagement with said object at said loading point.
 6. The system of claim 1 wherein said means feeding objects into said loader chute means includes means forming a stacking of said objects, said stack terminating at said loader chute means and also includes stripper means stripping the lowermost object from said stack and advancing said lowermost object down said loader chute means.
 7. The system of claim 6 wherein said stripper means includes a stripper blade narrower than the thickness of said objects as stacked, and means for reciprocating said stripper blade to cyclically strip off the lower-most object.
 8. The system of claim 1 wherein said locating and positioning means resists movements of said object at said loading points normal to said loader chute means.
 9. The system of claim 8 wherein said locating and positioning means includes spring retainer means engaging said object at said loading point.
 10. The system of claim 9 wherein said spring retainer means frictionally engages said object as it moves to said loading point.
 11. The system of claim 10 wherein said loader chute means includes guide rail means restraining said object at said loading point against movement caused by engagement with said object advanced into said recess and said movement of said fixture past said loading point. 